Steam trap monitoring

ABSTRACT

An apparatus and method for monitoring the status of a steam trap include a device for sensing a process condition of the steam trap and a device for processing the sensed condition. The apparatus can include a processor positioned on a steam trap. The connection of the monitoring device to the steam trap can be to the trap itself or to an adjacent pipe or other apparatus.

RELATED APPLICATIONS

This application is a Continuation application of U.S. patentapplication Ser. No. 11/199,042, filed Aug. 8, 2005 and entitled STEAMTRAP MONITORING which is a Continuation-In-Part application of U.S.patent application Ser. No. 11/006,789, filed Dec. 8, 2004, entitledREMOTE MONITOR FOR STEAM TRAPS, now U.S. Pat. No. 7,246,036.

TECHNICAL FIELD AND INDUSTRIAL APPLICABILITY OF THE INVENTION

The present invention relates in general to steam systems includingsteam traps and to steam trap monitoring.

BACKGROUND OF THE INVENTION

Steam traps are items of equipment common in factories, refineries andother industrial or commercial facilities. Steam traps are installed insteam lines and act to separate (remove) condensed steam, or“condensate”, from the steam without allowing the steam to escape. Theseparated condensate is then typically recycled back through condensatereturn lines to the boiler for conversion back to steam. To beeffectively operating, the steam trap must generally prevent steam fromescaping past the steam trap and entering the condensate return lines.If steam is allowed to pass through the steam trap into the condensatereturn line, the result is a loss of valuable energy and a reduction inthe efficiency of the steam system.

There are several well-known types of steam traps, including invertedbucket traps, float traps, thermostatic traps and disc traps.Manufacturing facilities, refineries and large buildings often arefitted with extensive systems of steam lines for heating and for processsteam. Some of these facilities can contain 1,000 or more steam traps.To promote efficient operation of the steam traps, some type ofmonitoring or inspection is required to detect malfunctioning traps.

In the past, several different methods of checking the condition ofsteam traps have been used. One system uses a battery powered probe tosense the temperature of the traps. Another system uses a batterypowered probe in an inverted bucket steam trap to sense the presence ofwater in the trap. When the inverted bucket steam trap has water in it,the trap has a state or condition referred to as “prime”. A properlyoperating inverted bucket trap must have a condition of prime if it isfunctioning properly. A requisite amount of water in the trap isindicative of proper steam trap operation. A known steam trap monitoringsystem includes a probe extending into a steam trap, the probe beingresponsive to the level of condensate in the steam trap.

Other existing steam trap systems include signal lights on the steamtraps indicative of the process conditions in the traps. Such systemsrequire visual inspection of all the steam traps in the entiremanufacturing facility for proper monitoring of all the steam traps.

Another system to monitor steam traps is a hard wire system whichincludes physical wiring that is threaded from each of the steam trapsto one or more centrally located steam trap control stations forreceiving and storing data concerning the process conditions of thesteam traps.

Still other methods for monitoring steam traps included the transmissionand reporting of data using radio frequencies.

SUMMARY OF THE INVENTION

One particular aspect of the invention relates to a method of monitoringthe status of a steam trap. The method includes sensing a processcondition of the steam trap by taking multiple readings of one or morestream trap parameters, processing the multiple readings using analgorithm in a processor mounted in a steam trap monitor positioned inthe vicinity of the steam trap, and transmitting a signal, based uponthe processed multiple readings, indicative of the process condition ofthe one or more steam trap parameters.

According to this invention there is also provided a method of attachinga monitor to a steam trap to monitor the status of the steam trap. Themethod includes providing a steam trap having a body and a cap, with thecap being attached to the body with at least one fastening mechanismwhich secures the cap to the body of the steam trap, removing thefastening mechanism, and securing a monitor to the cap with a connectordevice that replaces the fastening mechanism.

According to this invention there is also provided a method ofmonitoring the status of a steam trap, including adding a monitor mountto the steam trap, securing a probe member to the monitor mount, andsensing a process condition of the steam trap by taking multiplereadings of one or more stream trap parameters with the probe member.

According to this invention there is also provided apparatus formonitoring the status of a steam trap. The apparatus includes a monitorfor sensing process conditions of the steam trap by taking multiplereadings of one or more steam trap parameters. The monitor is positionedin the vicinity of the steam trap. The apparatus includes a processorconfigured to process the multiple readings using an algorithm, theprocessor being mounted in the steam trap monitor. The apparatus furtherincludes a transmitter for transmitting a signal indicative of theprocess conditions determined by the processor.

According to this invention there is also provided apparatus formonitoring the status of a steam trap. The apparatus includes a monitorfor sensing process conditions of the steam trap by taking multiplereadings of one or more steam trap parameters. The monitor is positionedin the vicinity of the steam trap. The apparatus includes a processorconfigured to process the multiple readings using an algorithm, theprocessor being mounted in the steam trap monitor. The apparatus furtherincludes a transmitter for transmitting a signal indicative of theprocess conditions determined by the processor.

According to this invention there is also provided a monitoring systemfor a steam trap, the monitoring system including a sensor device forsensing a process condition of a steam trap, an electronic monitoringdevice operatively connected to the sensor device to receive data fromthe sensor device, and a monitor mount configured to be connectable tothe steam trap and operable to convey a parameter of a steam trap toeither the sensor device or the electronic monitoring device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration, partially in phantom, of a steamtrap and a remote monitoring system.

FIG. 2 is a schematic illustration showing openings for probes in acoupling of a connector block of a remote monitoring system.

FIG. 3 is a schematic illustration, partially in phantom, of a steamtrap and a retro-fittable remote monitoring system.

FIG. 4 is a schematic illustration, partially in phantom, of a portionof the retro-fittable remote monitoring system shown in FIG. 3 takenalong line 4-4.

FIG. 5 is a schematic illustration, partially in phantom, of a steamtrap and another embodiment of a retro-fittable remote monitoringsystem.

FIG. 6 shows a flow diagram of the operating algorithm of the remotemonitoring system.

FIG. 7 is a schematic perspective illustration, partially in phantom, ofa steam trap and another embodiment of a retro-fittable remotemonitoring system.

FIG. 8 is a schematic perspective illustration of the retro-fittableremote monitoring system of FIG. 8.

FIG. 9 is a schematic perspective illustration of another retro-fittablemonitoring system for use with a steam trap.

FIG. 10 is a schematic perspective illustration of another embodiment ofa steam trap monitoring system.

FIG. 11 is a schematic perspective illustration of another embodiment ofa steam trap monitoring system.

FIG. 12 is a schematic front view of the saddle of FIG. 12.

FIG. 13 is a schematic front view of a linear saddle piece without aconcave surface.

DETAILED DESCRIPTION OF THE INVENTION

Steam traps are automatic mechanical valves that discharge condensate(water) from a steam system. In a live steam system, if a steam trapfails to function properly, there are two possible failures: 1) failed“open”, where an automatic valve in the steam trap is continuously inthe open condition allowing condensate and live steam to exit thesystem; or, 2) failed “closed” where the trap retains all the condensatein the system and sends such condensate back into the steam system,thereby reducing the efficiencies of the steam system and possiblydamaging the process equipment.

As shown in FIG. 1, one type of steam trap is generally indicated at 10.The depicted steam trap 10 is generally conventional and well known inthe art, although it is to be understood that the present invention maybe used with other types of steam traps. The steam trap 10 is connectedto a live steam line (not shown) which supplies steam into the steamtrap 10. The steam trap 10 is also connected to a condensate return line(not shown) to direct the condensate back to the steam generator, suchas a boiler (not shown). The steam trap 10 is connected to a remotemonitoring system 20.

In the embodiment shown, the remote monitoring system 20 includes amonitor mount in the form of a connector block 30, a temperature sensordevice 40, an acoustic sensor device 50, and a monitoring device 60. Asused in this description, the term “monitor mount” is intended toinclude, but not be limited to, any component suitable for the mountingof a monitoring device and/or sensor device and is operable to convey aparameter of a steam trap to a sensor or other device; such componentsmay include, connector blocks (couplings or collars), adapters, mountingblocks, saddles, or any other suitable components.

It should be noted that the temperature sensor device 40 and theacoustic sensor device 50 have been rotated in FIG. 1 to give a betterview of the temperature sensor device 40 and the acoustic sensor device50.

As used in this description, the term “remote” is intended to indicate,but not be limited to, a system including a sensor where the sensor islocated outside of the main body of a steam trap.

The connector block 30 allows the steam trap 10 to be installed in apiping configuration, i.e. connected to a steam line. The connectorblock 30 can be manufactured out of any suitable material that canwithstand normal steam trap working pressures and temperatures. Incertain embodiments, the connector block 30 is made of stainless steel.It is to be understood that suitable piping connections for theconnector block 30 can be NPT, PSPT, socket weld, butt weld or anyspecialty connection that is acceptably used in the steam trap industry.In certain embodiments, the connector block 30 can have a strainer (notshown) for debris removal.

The connector block 30 is operatively connected to the steam trap 10 ina suitable manner as will be understood by those skilled in the art. Inthe embodiment shown, the connector block 30 includes a coupling 22secured to a collar 24. The coupling 22 and collar 24 are in coaxialalignment with an inlet port 12 and an outlet port 14 in the steam trap10, as in a manner understood in the art. The collar 24 includes a steaminlet passage 25 and a steam outlet passage 27.

The coupling 22 of the connector block 30 includes a steam inlet passage31 that receives steam from the upstream steam system. The steam inletpassage 31 is in communication with the inlet passage 25 in the collar24, which, in turn, is in communication with the inlet port 12 in thesteam trap 10. The coupling 22 in the connector block 30 also includes asteam outlet passage 32 that receives recovered steam from the steamoutlet passage 27 in the collar 22 of the steam trap 10 and delivers therecovered steam to the downstream steam system. As is well understood,the supply of steam is diverted into the steam trap 10 where thecondensate is trapped or retained, and then removed from the system.

In one aspect of the present invention, the connector block 30 defines afirst orifice, or pocket 34 and a second orifice, or pocket 36, as shownin FIG. 2. The first and second pockets 34 and 36 each extend inwardfrom an outer surface 36 of the connector block 30. The first and secondpockets 34 and 36 terminate at closed ends 35 and 37, respectively. Theclosed ends 35 and 37 are in a spaced apart relationship to the inletand outlet passages 31 and 32 in the connector block 30.

The first pocket 34 has an interior dimension that readily accepts thetemperature sensor device 40. For example, the pocket 34 can be athreaded bore, as explained below, and the temperature sensor device 40can have a correspondingly threaded bolt. The temperature sensor 40 islocated within the connector block 30 in the first pocket 34 near theinlet passage 31 in the connector block 30. The temperature sensordevice 40 monitors the temperature of the steam entering the steam trap10. In an alternative embodiment, the first pocket 34 is near the outletpassage 32 and the temperature sensor 40 monitors the temperature of thesteam exiting the steam trap 10.

The second pocket 36 has an interior dimension that readily accepts theacoustic sensor device 50. For example, the second pocket 36 can be athreaded bore, as explained below, and the acoustic sensor device 50 canhave a correspondingly threaded bolt. The acoustical sensor device 50 islocated within the connector block 30 in the second pocket 36 in asuitable manner. The acoustical sensor device 50 monitors sound emittingfrom the steam trap.

As shown in FIG. 1 the temperature sensor device 40 and the acousticalsensor device 50 engage the closed ends 35 and 37. In the situationwhere the sensor devices 40 and 50 include threaded bolts, this meansthat the threaded bolts of the sensor devices 40 and 50 are threaded allthe way into the pockets 34 and 36 so that the end of the threaded boltseats or directly impinges on the closed ends 35 and 37. In the case ofthe acoustical sensor device 50 it has been discovered that generallybetter acoustical results are achieved when the acoustical sensor device50 engages the closed end 37, although such is not necessary.Alternatively, the temperature sensor device 40 and the acousticalsensor device 50 may be disposed in the first and second pockets 34 and36 without engaging the closed ends 35 and 37.

The monitoring device 60 is operatively connected to the temperaturesensor device 40 and to the acoustical sensor device 50. The monitoringdevice 60 receives data from the temperature sensor device 40 and theacoustic sensor device 50 and provides the monitoring logic for theindividual trap 10 to which it is connected. The monitoring device 60 isthus mounted to the connector block 30 via the temperature sensor device40 and the acoustical sensor device 50.

The monitoring device 60 can include any suitable enclosure for encasingthe sensing equipment required for operation of the system. Themonitoring device 60 may include any suitable programmable devicecapable of controlling the gathering, storage, and/or dissemination ofprocess condition data. In certain embodiments, a suitable sensorcontroller is a PIC 16C22 chip from Microchip. It is to be understoodthat various input devices can be connected to the sensor controller tosupply the sensor controller with data from the temperature sensordevice 40 and from the acoustic sensor device 50. For example,electrodes (not shown) can be connected via lead lines (not shown) fromthe monitoring device 60 to the temperature sensor device 40 and toacoustic sensor device 50 to provide input regarding the prime status(prime or no prime) of the steam trap 10. The monitoring device 60 canbe programmed to set a desired level for acceptable temperature andacoustical sensitivity.

Another embodiment of the present invention relates to a remotemonitoring system 120 that is especially useful for monitoring a steamtrap already connected to a steam system. Referring now to FIGS. 3 and4, a steam trap 110 is connected to a connector block 130, with theconnector block 130 being suitable to act as a monitor mount. The remotemonitoring system 120 can be installed between the steam trap 110 and analready hard piped connector block 130. The remote monitoring device 120provides a cost effective and technologically advanced monitoring systemfor existing trap populations.

In the embodiment shown in FIGS. 3 and 4, the connector block 130 isoperatively connected to the steam system in a suitable manner as willbe understood by those skilled in the art. The connector block 130includes a coupling 122 secured to a collar 124. The coupling 122 andcollar 124 (the monitor mount) are in general coaxial alignment witheither an inlet port 112 or an outlet port 114 in the steam trap 110, ina manner understood in the art. The collar 124 includes a steam inletpassage 125 and a steam outlet passage 127.

The coupling 122 of the connector block 130 includes a steam inletpassage 131 that receives steam from the upstream steam system. Thesteam inlet passage 131 is in communication with the inlet passage 125in the collar 124, which is, in turn, in communication with the inletport 112 in the steam trap 110. The connector block 130 also includes asteam outlet passage 132 that receives recovered steam from the steamoutlet passage 127 in the collar 122 of the steam trap 110 and deliversthe recovered steam to the downstream steam system. As is wellunderstood, the supply of steam is diverted into the steam trap 110where condensate is trapped and removed from the system.

The collar 124 of the connector block 130 defines a first orifice, orpocket, 134 which extends radially inward from an outer surface 136 ofthe collar 124. The first pocket 134 terminates at a closed end 135. Theclosed end 135 is in a spaced apart relationship to the inlet passage131 and the outlet passage 132 in the connector block 130.

The first pocket 134 has an interior dimension that readily accepts aprobe 139. As shown in FIG. 4, the first pocket 134 is a threaded boreengaging threads on the exterior of the probe 139. It must be understoodhowever, that the probe 139 may be secured in the first pocket 134 inany suitable manner. The probe 139 can include a temperature sensor 140and/or an acoustic sensor 150. As shown, the probe 139 is located withinthe first pocket 134 near the outlet passageway 127 in the connectorblock 130. Thus, the temperature sensor device 140 within the probe 139may monitor the temperature of the steam exiting the steam trap 110.Likewise, the acoustical sensor device 150 within the probe 139 monitorssound emitting from the steam trap 110. Alternatively, the probe 139 maybe located near the inlet passageway 125 and the temperature sensorwould thus monitor the temperature of the steam entering the steam trap110.

The probe 139 is operatively connected to a monitoring device 160 insuch a manner that the monitoring device 160 receives data from thetemperature sensor device 140 and the acoustic sensor device 150 andprovides the monitoring logic for the individual trap 110 to which it isconnected.

Another embodiment of the present invention relates to a remotemonitoring system 220 that is especially useful for monitoring a steamtrap already connected to a steam system. Referring now to FIG. 5, asteam trap 210 is connected to a connector block 230, where theconnector block 230 is suitable to operate as a monitor mount, whichmeans that the connector block 230 is operable to convey a parameter ofa steam trap to either the sensor device or the electronic monitoringdevice.

In the embodiment shown in FIG. 5, the connector block 230 isoperatively connected to the steam system in a suitable manner as willbe understood by those skilled in the art. The connector block 230includes a coupling 222 that is in a spaced apart relationship to acollar 224. The coupling 222 and collar 224 are in general coaxialalignment with either an inlet port 212 or an outlet port 214 in thesteam trap 210, as in a manner understood in the art. The collar 222includes a steam inlet passage 225 and a steam outlet passage 227.

The coupling 222 of the connector block 230 includes a steam inletpassage 231 that receives steam from the upstream steam system. Thesteam inlet passage 231 is in communication with the inlet passage 225in the collar 224, which is, in turn, in communication with the inletport 212 in the steam trap 210. The coupling 222 of the connector block230 also includes a steam outlet passage 232 that receives recoveredsteam from the steam outlet passage 227 in the collar 222 of the steamtrap 210 and delivers the recovered steam to the downstream steamsystem. As is well understood, the supply of steam is diverted into thesteam trap 210 where condensate is trapped and removed from the system.

A monitoring device 260 is generally coaxially positioned between thecoupling 222 and the collar 224. The electronic monitoring device 260can include a temperature sensor 240 and/or an acoustic sensor 250. Thetemperature sensor device 240 monitors the temperature of the steamentering the steam trap 210. Likewise, the acoustical sensor device 250monitors sound emitting from the steam trap 210 during the service lifeof the steam trap 210.

As shown in FIG. 5, the monitoring device 260 is installed in theconnector block 230, e.g. disposed between the coupling 222 and thecollar 224. It must be understood, however, that the monitoring device260 can be installed in any suitable location, such as between the steamtrap 210 and an already hard piped connector block 230, e.g. between thesteam trap 210 and the collar 224, or between the connector block 230and a steam pipe (not shown).

The remote monitoring device 220 provides a cost effective andtechnologically advanced monitoring system for existing trappopulations, and therefore the ability to add the remote monitoringsystem in a retrofit situation is highly beneficial.

The temperature sensor 240 and the acoustic sensor 250 are operativelyconnected to the monitoring device 260 in such a manner that themonitoring device 260 receives data from the temperature sensor device240 and the acoustic sensor device 250, and provides the monitoringlogic for the individual trap 210 to which it is connected.

One or more other input devices for monitoring parameters associatedwith process conditions can be included in the connector block. Such aninput device can be, for example, a pressure switch that is connected tothe sensor controller in a suitable manner. Any suitable connection canbe used. The pressure switch senses the pressure within the steam line,and this information is supplied to the sensor controller. Pressureswitches are well known to those skilled in the art of steam processinstrumentation. In addition to the process condition sensing devicesdescribed above (pressure, temperature and prime), other sensors, notshown, could be employed to sense other process conditions.

The system also optionally includes a method by which the electroniccircuitry of the monitoring device is programmed to learn the individualoperational characteristics of the individual steam trap connected tothe connector block. The method includes monitoring tolerance levels toestablish an upper tolerance level and a lower tolerance level thatrepresent acceptable operational sound or acoustic levels for thespecific type and application of the individual trap.

The method also optionally includes monitoring minimum temperatureswithin the steam trap to check for proper operational temperatures. Thechecks, or queries, are made on a regular basis to minimize energy lossin the event of steam trap malfunction. During the query, comparisons ofactual sound levels are made to the sound levels created by the steamtrap during the initial set-up. If the acoustical comparison is withinthe upper and lower limits of the baseline sounds, the query stops and anew query is initiated again per a predetermined schedule.

If the operational sound levels collected during a query are outside theupper or lower limits, an accelerated query schedule is conducted. Ifthe queries consistently exceed the upper or lower sound limits, thesteam trap is identified as a maintenance item.

The temperature sensor will sense if the steam temperature has reached aminimum temperature of 212° F. (normal minimum for steam to be presentat atmospheric pressure). The temperature sensor senses hot (>212° F.)or cold (<212° F.) and relays that data to the monitoring device. Thisdata, in turn, is used to determine if the trap connected to theconnector block is located on an active (live) steam line. Themonitoring device obtains data from the temperature sensor and acousticsensor and transmits such data to a receiver (not shown) connected to abase computer (not shown). This information, once reported to the basecomputer, can be automatically accessed via the Internet for offsiteremote monitoring. This information can be transmitted at set intervalsto maintain efficiencies in the steam system.

In certain embodiments, the present invention includes monitoring thestatus where the averaged signals transmitted from the steam traps aretransmitted periodically, and the transmitters emit signals of differingfrequency to provide diversity. In certain systems, the method includestaking a predetermined number of readings (in certain embodiments, atleast 4 readings) to calculate the average of the process condition ofthe steam trap. Also, the period of time between successive averaging ofsensing process condition can be any suitable time period, such as, forexample, within the range of from about 0.2 to about 5 seconds, and theperiod between successive steps of transmitting signals to the receivercan be any suitable range, such as, for example, within the range offrom about 0.5 to about 300 seconds. Other periods can also be used. Thesystem can be optionally set up so that the transmitter periodicallytransmits a signal indicative of the process condition to the receiverwhen the sensed process condition is within programmed limits, but wherethe signal from the transmitter is transmitted to the receiverimmediately upon detection of a condition outside the programmed limits.

It is to be understood that the transmission and reporting of data viaradio frequency systems can be conducted using technology understood inthe art. In certain embodiments, a transmitter microprocessor and amicroprocessor-based radio frequency transmitter are positioned withinthe electronic monitoring device. The transmitter microprocessorreceives input from the sensor controller. The transmitter transmits anappropriate radio frequency (RF) signal responsive to the sensed processconditions. The transmitter microprocessor can be any suitable devicethat is programmable and is capable of receiving the output from thesensor controller. A suitable transmitter microprocessor is a model68HC05 microprocessor by Motorola. The transmitter can be any suitabledevice for transmitting an appropriate radio frequency signal (or theretype of signal) responsive to the condition of the steam trap. Apreferred transmitter is a model FA 210 universal transmitter byInovonics Corporation, Boulder, Colo. It is to be understood that asingle programmable microprocessor can be used to control both thesensing and transmitting functions.

Also, optionally a battery can be provided within the electronicmonitoring device to provide power to the components within themonitoring device. Any suitably sized battery, such as a 3-volt battery,can be used. The programmable sensor controller and the programmabletransmitter can be programmed to operate periodically but for only shortperiods of time, so that current is drawn from the battery for onlyperiods of short duration. This method greatly prolongs the life of thebattery, thereby lengthening the time before servicing the steam trapmonitoring system is required. Preferably, the monitoring system is asend only system, capable of sending signals but not receiving signals.To receive signals, the monitor would have to be fitted with a receiverthat would have to be activated or powered either continuously, orperiodically, thereby causing an additional drain on the battery, andshortening the service life of the battery. By designing the steam trapsto have no means for receiving signals from a separate signaling device,such as a remote transmitter, the efficiency of the system is enhanced.It is to be understood, however, that the monitors could also beprovided with receivers, not shown.

In operation, the monitoring system of the invention transmits an RFsignal directed toward a receiver. The receiver can be any suitabledevice for picking up the RF signal. It is to be understood that thecharacteristics of the receiver must be matched to those of thetransmitter to provide a proper communications link and optimal RFperformance. A preferred receiver is an Inovonics FA403 receiver.Associated with the receiver is a data-handling device, such as acomputer (not shown) for storing and displaying data from the steamtrap. Preferably, the computer is adapted to provide alarms, reports orother indications when steam traps are determined to be malfunctioning.

In some installations of the monitoring system the distance between thesteam trap and the receiver will be so great that the RF signal will betoo weak or attenuated at the receiver for reliable data transmission.Therefore, the system can include a repeater (not shown) positionedbetween the steam trap and the receiver. The repeater receives the RFsignal from the transmitter, amplifies the signal and rebroadcasts thesignal. Suitable repeaters are commercially available from Inovonics.The repeater should also be matched to the characteristics of thetransmitter and receiver to provide a working communications link. Apreferred repeater is a model 525 repeaters by Inovonics. The repeaterreceives the signal from the steam trap monitor and re-broadcasts thesignal with enough strength to reach the receiver. It is to beunderstood that several repeaters can be used in series to extend thelength between remote steam traps and the receiver.

Another optional aspect of the monitoring system is that it can beconfigured so that it can remotely monitor the steam trap and learn theindividual operational characteristics of the steam trap. Theprogrammable sensor controller can be programmed with an algorithm whichtests or senses various process conditions at the initial start-up andthen throughout the operation of the steam trap.

In a specific embodiment of the invention, the remote monitoring systemactively determines the process conditions and establishes the status ofthe steam traps within a period of active time, and remains inactive fora period of inactive time. The result of such process conditionmonitoring is a status of the steam trap within desired parameters. Thestatus of the steam trap is then transmitted to the transmittermicroprocessor.

The transmitter and programmable transmitter microprocessor operatesomewhat independently of the remote monitoring system. The transmittermicroprocessor is programmed to look at or sense the status of the steamtrap as reported by the remote monitoring system. This sensing orsampling by the transmitter microprocessor occurs periodically, such asperhaps once every half second. The transmitter periodically transmitsan RF signal indicative of the status of the steam trap. Thetransmitting of the RF signal can be accomplished with a perioddifferent from the period of the sampling by the transmittermicroprocessor. Preferably, the period between successive steps oftransmitting signals to the receiver is within the range of from about0.5 to about 300 seconds. However, upon detection of a condition outsidethe programmed limits, the signal from the transmitter is transmitted tothe receiver immediately.

One suitable operating algorithm is shown in FIG. 6. It is to beunderstood that different algorithms could be used to operate the systemof the invention. At start-up the circuit is powered up, and a sensormakes a determination of whether there is pressure in the steam lineadjacent the steam trap. If not, the status is OK, and the system isprogrammed to go to sleep for a period of time, such as, for example, 1hour, before waking up. If the steam line is pressurized, another sensormakes a determination of whether the steam trap is hot. This can bedetermined in any number of ways, such as if the temperature of thesteam trap exceeds a specific threshold temperature. If the steam trapis not hot, the status is COLD, and the system is programmed to go tosleep for a period of time, such as, for example, 1 hour, before wakingup.

If the steam line is pressurized and the steam trap is hot, then theTrap State History counter is set at an initial value of zero, and theAnalog Circuit is switched on. Multiple readings or samples are taken ofone or more parameters, such as the condensate level or acousticalcondition of the steam trap. For example, 20 samples of voltage outputfrom a sensor or circuit associated with the condensate level oracoustical condition, or any other parameter of the steam trap, can besampled. Any number of samples can be taken in a series or group ofsamples. These can be taken rapidly, such as one each 5 ms, or at anyother interval.

In one particular embodiment, the algorithm is configured to determinewhether or not a predetermined percentage of the samples exceeds athreshold percentage. For example, the algorithm may be configured todetermine if 25 percent or more of the samples have voltage values thatare less than specified voltage, with the specified voltage beingindicative that the steam trap is open. If less than a predeterminedpercentage of sample readings (for example, less than 25 percent of thesample readings) have a voltage less than the specified voltage, thenthe system indicates that the Trap Status is CLOSED, and the trap is OK.In that case, the circuit is shut down for one hour, at which time theAnalog Circuit is turned on and more samples are taken.

If, on the other hand, the predetermined percentage of sample readings(for example, 25 percent of the readings) have a voltage that is belowthe specified voltage, then there is an indication that the steam trapmay be compromised. In that case, the Trap State History counter isindexed by one increment. If the resulting Trap State History counterhas a value that is less than 5, that means that there have not been 5indications of trap failure, and consequently there is insufficientevidence that the trap is compromised. Accordingly, the system is shutdown for a period of time, such as 5 minutes, and then the AnalogCircuit is turned on and the sequence is repeated, with more samplesbeing taken.

If the resulting Trap State History counter has a value of 5, that meansthat there have been 5 indications of trap failure, and there is nowsufficient evidence that the trap is compromised. Accordingly, the traphas been open too long, and the trap is in a BLOW THROUGH condition, andan appropriate signal is transmitted.

In another aspect, as shown in FIGS. 8-10, the present invention relatesto a retrofittable remote monitoring system 320 that is especiallyuseful for monitoring a steam trap already connected to a steam system.The retrofittable remote monitoring system 320 provides a cost effectiveand technologically advanced monitoring system for use on existing trappopulations. While FIGS. 8 and 10 show an inverted bucket type of steamtrap, it should be understood that it is also within the contemplatedscope of the present invention that the retrofittable remote monitoringsystem can be installed on other types of steam traps.

In another aspect, the present invention relates to a method forretrofitting a steam trap with a remote monitoring system.

Referring now to FIG. 8, a steam trap 310 is connected to a live steamline (not shown) which supplies steam into the steam trap 310. The steamtrap 310 is also connected to a condensate return line (not shown) todirect the condensate back to the steam generator, such as a boiler (notshown). The steam trap 310 includes a cap 312 and a body 314. The cap312 of the steam trap 310 is secured to the body 314 with one, and oftena plurality of fastening mechanisms, such as a bolt 316. The cap 312generally defines one or more openings 318, each of which receives acorresponding fastening mechanism 316.

A monitoring device 360 is operatively connected to the steam trap 310by means of one or more connector devices. One example of a connectordevice is a probe member 370 that senses or relays one or more processconditions associated with or within the steam trap 310. The probemember 370 is operatively connected to monitoring devices such as atemperature monitor or sensor device 340 or an acoustic monitor orsensor device 350 within or associated with the monitoring device 360.The temperature monitor 340 monitors the temperature of the steamentering the steam trap 310 via the probe member 370. Likewise, theacoustical monitor 350 monitors sound emitting from the steam trap 310via the probe 370.

The temperature monitor 340 and the acoustic monitor 350 are operativelyconnected within the monitoring device 360 in such a manner that themonitoring device 360 receives data from the temperature sensor device340 and the acoustic sensor device 350. Further, the monitoring device360 may provide the monitoring logic for the individual trap 310 towhich it is connected.

In the embodiment shown in FIGS. 8 and 9, the probe member 370 sensesone or more process conditions within the steam trap 310. The probemember 370 extends from a housing 362 of the monitoring device 360 andinto the cap 312 and the body 314 of the steam trap 310. The probemember 370 is preferably made of a material that is capable ofconducting temperature and/or acoustic changes within the steam trap.Suitable materials include, for example, heat and sound conductingmetals and the like. It is to be understood that in its simplest formthe connector device and the probe itself can be merely a threaded boltthat connects the monitoring device 360 with the steam trap.

The probe member 370 can be secured to the cap 312 by one or moresecuring mechanisms, shown as an upper securing mechanism 374 and alower securing mechanism 376, which are shown as nuts. However, it mustbe understood that the securing mechanism may be any suitable securingmechanism, such as rivets, welds, or a clinched arrangement. The probemember 370 is operatively connected to the temperature sensor 340 and/orthe acoustic sensor 350.

In one embodiment, the monitoring device 360 is connected to the steamtrap 310 as follows. A fastener 316 is removed from one of the openings318 in the cap 312. A connector device, in the form of the probe member370 or any other suitable connector device, is then inserted into theempty opening 318. In certain embodiments, the probe member 370 can havea threaded configuration such that the monitoring device 360 can bescrewed into the cap and/or body of the steam trap and no steam isallowed to escape from the steam trap 310. It is to be understood,however, that other means for preventing the loss of steam from thesteam trap 310 through the opening 318 are within the contemplated scopeof the present invention. The probe member 370 is positioned within theopening 318 in the cap 312 such that the probe member 370 remains at adesired depth within the steam trap 310 once the cap 312 is againsecured to the body 314. In the embodiments shown, the upper securingmechanism 374 is secured against a top surface of the cap 312 and thelower securing mechanism 376 is secured against a bottom surface of thecap 312.

In another aspect, the present invention relates to a method ofmonitoring the status of a steam trap. The fastening mechanism 316 ofeither an existing or a new steam trap is replaced with a connectordevice. The connector device connects the steam trap with a monitor tomonitor a process condition within the steam trap. Alternatively, theconnector device can be a probe member 370 that is secured to the steamtrap such that a portion of the probe member 370 extends through the capand into the body of the steam trap, thus not being a remote monitor.One or more process conditions in the steam trap are sensed with theprobe member 370. A signal responsive to the sensed process condition ofthe steam trap is then transmitted. The method can also includetransmitting averaged signals from the steam trap.

In another embodiment, as shown in FIG. 10, an apparatus 420 formonitoring the status of the steam trap includes a monitoring device 460operatively attached to a steam trap 410. The embodiment shown in FIG.10 shows several features that can be used alone or in combination, andsuch uses of the feature or multiple features are within thecontemplated scope of the present invention. The monitoring device 460is directly attached to the steam trap 410. The monitoring device 460includes one or more probe members 470 that extend from a housing 462 ofthe monitoring device 460. The probe member 470 acts as a temperaturesensor and/or an acoustic sensor.

The probe member 470 is positioned within one opening 418 of the steamtrap 410. In certain embodiments, the probe member 470 can have athreaded configuration such that no steam is allowed to escape from thesteam trap 410. It is to be understood, however, that other means forpreventing the loss of steam from the steam trap 410 through the opening418 are within the contemplated scope of the present invention. Theprobe member 470 is positioned within the opening 418 such that theprobe member 470 remains at a desired depth within the steam trap 410.In the embodiment shown, the probe member 470 can be hollow, defining anopening or passageway 472, shown in phantom in FIG. 10, to allow for thedetection of pressure within the steam trap 410. In certain embodiments,a pressure sensing device 480 is positioned in the opening to sensepressure within the steam trap 410.

In yet another embodiment, as shown in FIG. 11, an apparatus 520 formonitoring the status of a steam trap includes a monitor mount. Themonitor mount may be any component suitable for the mounting of amonitoring device and/or sensor to a steam trap. The monitor mount isoperable to convey a parameter of a steam trap to the sensor or othermonitoring device. The monitor mount is shown in the form of a mountingblock 581, although other forms are possible.

The apparatus 520 for monitoring the status of a steam trap includes amonitoring device 560 operatively attached to the mounting block 581.The monitoring device 560 may include one or more probe members 570 thatextend from a housing 562 of the monitoring device 560. The probe member570 acts as a temperature sensor and/or an acoustic sensor.Alternatively, the probe member may act as a carrier or intermediary fora separate sensor, such as a temperature sensor and/or and acousticsensor, to convey one or more parameters from the steam trap to themonitoring device.

The mounting block 581 includes an attachment bore 582 and a probe boreor pocket 583. The mounting block 581 is secured to a steam trap 510 bya fastener 516 through the attachment bore 582. It must be understood,however, that the mounting block need not include the attachment bore582 or be secured by the fastener 516. The mounting block 581 may besecured to the steam trap 510 in any suitable manner, such as byriveting, by welding, or by clinching. The monitoring device 560 isconnected to the mounting block 581 by a probe 570 disposed in the probebore 583. The probe 570 may be disposed in the probe bore 583 in anysuitable manner, such as by threaded engagement, by welding or byclinching.

The mounting block 581 is preferably made of a material that is capableof conveying a parameter of a steam trap, such as conducting temperatureand/or vibrating acoustic changes within or associated with the steamtrap 510, or any other suitable conveyance of any parameter. It must beunderstood, however, that the mounting block 581 may be made of anysuitable material.

In another embodiment, as shown in FIGS. 12 and 13, an apparatus 620 formonitoring the status of a steam trap 610 includes a monitoring device660 operatively attached to a monitor mount in the form of a saddle 685.The monitoring device 660 may include one or more probe members 670 thatextend from a housing 662 of the monitoring device 660. The probe member670 acts as a temperature sensor and/or conveyor and/or an acousticsensor and/or conveyor.

The saddle 685 is attached to a pipe 687 connected to the steam trap610. The pipe 687 may be a steam inlet line, a steam outlet line, acondensate return line, or any other suitable pipe or mechanical memberconnected to the steam trap 610. It must be further understood that thesaddle need not be connected to the pipe 687 and may be connecteddirectly to the steam trap 610, or any other suitable componentconnected to the steam trap 610. Therefore, for purposes of thisinvention, the terminology “monitor mount configured to be connected tothe steam trap” includes monitor mounts connected directly to the steamtrap, as illustrated at 581 in FIG. 11, as well as monitor mountsconnected adjacent to the steam trap via an external member, such as thesaddle 685 attached to the pipe 687 or similar adjacent members (steaminlet line, a steam outlet line or a condensate return line) illustratedin FIGS. 12-13.

The saddle 685 is shown as a two piece saddle including first and secondpieces 685 a and 685 b that are secured to the pipe 687 in a clampingarrangement by two threaded fasteners 688. It must be understood,however, that the saddle 685 need not be secured by a clampingarrangement. The saddle 685 may be secured to the pipe 687, or any othersuitable component, in any suitable manner, such as by rivets, bywelding, or by a clinched arrangement.

The saddle 685 includes a probe bore or pocket 683. The monitoringdevice 660 is connected to the saddle 685 by the probe 670 disposed inthe probe bore 683. The probe 670 may be disposed in the probe bore 683in any suitable manner, such as by threaded engagement, by welding or byclinching.

The saddle 685 is preferably made of a material that is capable ofconducting temperature and/or acoustic changes within or associated withthe steam trap 610, thus acting as a monitor mount. It must beunderstood, however, that the saddle 685 may be made of any suitablematerial. The saddle 685 may be suitable to be a monitor mount so longas the saddle 658 is suitable for the mounting of a monitoring deviceand/or sensor, and operable to convey a parameter of a steam trap to thesensor or another device.

As shown in the embodiment illustrated in FIGS. 12-13, at least one ofthe saddle pieces 685 a and 685 b optionally has a concave surface 690to enable secure contact with the pipe 687, regardless of the diameterof the pipe 687. The surface 690 can be a pair of flat beveled surfaces,as shown, or can be semispherical, elliptical, or any otherconfiguration enabling solid contact between the pipe 687, or otherstructure, and the saddle 685. A solid connection increases the thermaland acoustical conduction of the saddle 685 and ultimately for themonitoring device 660.

The face of the concave surface 690 can be smooth, or can be irregularfor improved gripping and contact with the pipe 687. While both thefirst and second saddle pieces 685 a and 685 b are shown as havingconcave surfaces 690, the saddle 685 can be configured with only one ofthe saddle pieces 685 a or 685 b having a concave surface 690.

Further, the saddle 685 may be configured without any concave pieces.For example, the saddle 685 may alternatively include a linear saddlepiece 685 a′, as shown in FIG. 14. The linear saddle piece 685 a′includes a plurality of optional extending members for securelyconnecting to the pipe 687.

It can be seen from the above disclosure that in at least one of itsembodiments the invention involves a method of remotely monitoring steamtraps using signaling to communicate the process conditions of the steamtraps to a centralized receiving station. The system for remotelymonitoring a steam trap in a working, or live steam, system can includea monitoring apparatus capable of being attached to the steam trap or toa steam line. In certain aspects, the present invention is useful in newconstruction and/or re-piping situations where the apparatus is capableof being attached to a number of different styles of steam traps thatare to be remotely monitored. In certain other aspects, the presentinvention is useful for installation onto existing steam traps alreadyin place and currently being used for monitoring a live steamenvironment. In certain embodiments, the system includes a monitoringapparatus that adapts to an existing style of steam trap. The apparatusmonitors the operational status of the steam trap and then communicatessuch information in a wireless transmission to a remote site.

The description of the invention above has been primarily focused on theuse of temperature and acoustical sensors, such as temperature andacoustical sensors 40, 50, to sense conditions in the steam trap. It isto be understood that other sensors, such as pressure sensors, can beused to sense a condition of the steam trap. Also, when a temperature orpressure is sensed, the sensed medium can be steam, air, or water(condensate), or can be the temperature of the steam trap itself, or ofa closely linked apparatus, such as adjacent piping or a connectorblock. Accordingly, a sensor device for sensing the temperature of thesteam trap includes sensing the trap or related adjacent apparatusassociated with the trap. Also, a sensor device for sensing soundemitting from the steam trap includes sensing sound from the trap orrelated adjacent apparatus. Likewise, a sensor device for sensing thepressure in the steam trap includes sensing the pressure in closelyassociated apparatus.

The principle and mode of operation of this invention have beendescribed in its preferred embodiment. However, it should be noted thatthis invention may be practiced otherwise than as specificallyillustrated and described without departing from the scope of theinvention.

What is claimed is:
 1. A method of monitoring the status of a steam trapcomprising: sensing a process condition of at least one of a temperaturecondition, an acoustical condition, or a pressure condition of the steamtrap by taking multiple readings of one or more stream trap parameters,the process condition representing a continuum of values between anuppermost process condition limit and a lowermost process conditionlimit; selecting a threshold level for the sensed process condition, thethreshold level having a adjustable value between the upper processcondition limit and the lower process condition limit; processing themultiple readings using an algorithm in a processor mounted in a steamtrap monitor positioned in the vicinity of the steam trap, wherein theprocessing includes: a) determining if the sensed process conditionexceeds the threshold level; b) continuing to sense the processcondition for a pre-determined number of readings after determining thatthe threshold level has been exceeded by the sensed process condition;and c) comparing the sensed process condition from each of thepre-determined number of readings to the threshold level; and d)returning to the step of sensing the process condition of the steam trapwhen the sensed process condition again falls below the threshold levelbefore the predetermined number of readings are completed; andtransmitting a signal, based upon the processed multiple readings,indicative of determining one of a transient or steady state status ofthe process condition of the one or more steam trap parameters.
 2. Themethod of claim 1, in which signals that are indicative that the processcondition is within a programmed limit are transmitted at predeterminedintervals, and in which signals that are indicative that the processcondition is outside the programmed limit are transmitted immediatelyupon detection.
 3. The method of claim 1 in which the algorithm includesdetermining whether or not a predetermined percentage of the readingsfor a parameter have values that exceed a threshold level for the sensedcondition.
 4. The method of claim 1, wherein when the threshold level isexceeded for each of the pre-determined number of readings, a signal isgenerated.
 5. A method of a monitoring the operational characteristicsof a steam trap comprising: connecting a monitoring device to a specificsteam trap unit; programming the monitoring device to learn theindividual operational characteristics of the specific steam trap unit;operating the steam trap unit during an initial set up period; sensing aprocess condition that is representative of the operationalcharacteristics of the specific steam trap unit during the initial setup procedure by taking multiple readings of one or more stream trapparameters, the process condition being at least one of a temperaturecondition, an acoustical condition, or a pressure condition, the processcondition representing a continuum of values between an uppermostprocess condition limit and a lowermost process condition limit;determining an upper tolerance level and a lower tolerance level of thesensed process condition for the specific steam trap unit, the upper andlower tolerance levels being selectable values between the uppermostprocess condition limit and the lowermost process condition limit;initiating a query to determine whether the process condition is one ofa transient status or a steady state status process condition of thesteam trap and sensing the process condition of the specific steam trapunit during operation after the initial set up period; comparing thesensed process condition of the specific steam trap unit after theinitial set up period with the upper and lower tolerance levels; andgenerating a signal when the sensed process condition is outside of theupper and lower tolerance levels.
 6. The method of claim 5 wherein thequery is conducted on a regular basis during operation after the initialset up period.
 7. The method of claim 6 wherein the regular basis ofconducting queries is a predetermined schedule that is included in theprogramming of the monitoring device.
 8. The method of claim 7 wherein astep of initiating a new query according to the predetermined scheduleis taken by the monitoring device if the sensed process condition iswithin the upper and lower tolerance level.
 9. The method of claim 5wherein the step of comparing the sensed process condition includesdetermining if the sensed process condition is within the upper andlower tolerance level.
 10. The method of claim 9 wherein sensing theprocess condition includes taking multiple readings of the processcondition.
 11. The method of claim 5 wherein the sensed processcondition is a temperature measurement and the method includes a step ofdetermining if the steam trap is connected to a connector block that islocated on an active steam line based on the temperature measurement.12. The method of claim 5 wherein the step of connecting a monitoringdevice to a specific steam trap unit includes connecting the monitoringdevice to a radio frequency transmitter.
 13. The method of claim 12wherein the step of comparing the sensed process condition of thespecific steam trap unit after the initial set up period with the upperand lower tolerance level includes transmitting a signal, based upon theprocessed multiple readings, indicative of the process condition of theone or more steam trap parameters.
 14. The method of claim 13 whereinthe step of transmitting a signal further includes the transmitterperiodically transmitting the signal indicative of the process conditionto the receiver when the sensed process condition is within programmedlimits and transmitting the signal to the receiver immediately upondetection of a condition outside the programmed limits.
 15. The methodof claim 14 wherein the receiver is connected to a base computer, andthe base computer is Internet accessible.